Fix flaky testCreateBlankPage

[kean]

Fixes testCreateBlankPage().

To test:

RCA

• setUpTestSuite(selectWPComSite: WPUITestCredentials.testWPcomFreeSite) launches the app and nearly instantly logs the user in (which is awesome – thank you!)
• The app fetches the list of pages and transition the test scenario to the initial_pages_list state
• The app calls try await WireMock.setUpScenario(scenario: "new_page_flow") and reset the scenario state back to "Started"

As a result, the mock server returns the following error when you try to upload a post:

                                               Request was not matched
                                               =======================

-----------------------------------------------------------------------------------------------------------------------
| Closest stub                                             | Request                                                  |
-----------------------------------------------------------------------------------------------------------------------
                                                           |
POST                                                       | POST
[path] /rest/v1.2/sites/181851495/posts/new                | /rest/v1.2/sites/181851495/posts/new?context=edit&locale=
                                                           | en
                                                           |
Query: context = edit                                      | context: edit
Query: locale = en                                         | locale: en
                                                           |
[Scenario 'new_page_flow' state: initial_pages_list]       | [Scenario 'new_page_flow' state: Started]           <<<<< Scenario does not match
            

It's a race condition and it depends on whether the pages are fetched before or after the reset happens.

Regression Notes

1. Potential unintended areas of impact

2. What I did to test those areas of impact (or what existing automated tests I relied on)

3. What automated tests I added (or what prevented me from doing so)

PR submission checklist:

• I have completed the Regression Notes.
• I have considered adding unit tests for my changes.
• I have considered adding accessibility improvements for my changes.
• I have considered if this change warrants user-facing release notes and have added them to RELEASE-NOTES.txt if necessary.

Testing checklist:

• WordPress.com sites and self-hosted Jetpack sites.
• Portrait and landscape orientations.
• Light and dark modes.
• Fonts: Larger, smaller and bold text.
• High contrast.
• VoiceOver.
• Languages with large words or with letters/accents not frequently used in English.
• Right-to-left languages. (Even if translation isn’t complete, formatting should still respect the right-to-left layout)
• iPhone and iPad.
• Multi-tasking: Split view and Slide over. (iPad)

[wpmobilebot]

📲 You can test the changes from this Pull Request in WordPress Alpha by scanning the QR code below to install the corresponding build.

	App Name	WordPress Alpha
	Configuration	Release-Alpha
	Build Number	pr22983-5dcac5b
	Version	24.6
	Bundle ID	org.wordpress.alpha
	Commit	5dcac5b
	App Center Build	WPiOS - One-Offs #9448

Automatticians: You can use our internal self-serve MC tool to give yourself access to App Center if needed.

[wpmobilebot]

📲 You can test the changes from this Pull Request in Jetpack Alpha by scanning the QR code below to install the corresponding build.

	App Name	Jetpack Alpha
	Configuration	Release-Alpha
	Build Number	pr22983-5dcac5b
	Version	24.6
	Bundle ID	com.jetpack.alpha
	Commit	5dcac5b
	App Center Build	jetpack-installable-builds #8491

Automatticians: You can use our internal self-serve MC tool to give yourself access to App Center if needed.